WTPA42 PHFO 210929
TCDCP2

HURRICANE NEKI DISCUSSION NUMBER  11
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   CP032009
1100 PM HST TUE OCT 20 2009

NEKI HAS MAINTAINED AN EYE AND HAS CONTINUED TO INTENSIFY RAPIDLY. 
FIXES FROM PHFO...SAB...AND JTWC WERE 4.0...4.5 AND 4.5. WE HAVE
MADE THE INITIAL INTENSITY 75 KT. A RECENT QUIKSCAT PASS SHOWED A
VERY ASYMMETRIC WIND FIELD WITH 35 KT WINDS EXTENDING MUCH FARTHER
OUT ON THE NORTHEAST AND SOUTHEAST SIDES OF THE STORM. WE HAVE MADE
MAJOR CHANGES IN THE WIND RADII TO REFLECT THIS PATTERN.
 
NEKI CONTINUES MOVING TO THE NORTHWEST TOWARD A WEAKNESS IN THE
SUBTROPICAL RIDGE. THE MODEL TRACK GUIDANCE HAS CONTINUED TO
SHIFT...WITH MORE OF THE MODELS SHOWING NEKI GRADUALLY RECURVING.
THE MODELS SHOW A SERIES OF TROUGHS ALOFT AND ASSOCIATED SURFACE
FRONTS DIGGING TOWARD THE HURRICANE FROM THE NORTHWEST. THE DEEP
LAYER MEAN FLOW WILL VEER AHEAD OF THESE SYSTEMS AND NEKI WILL
CURVE TOWARD THE NORTH AND EVENTUALLY TOWARD THE NORTH NORTHEAST.
WE HAVE ADJUSTED THE FORECAST TRACK TO THE RIGHT...CLOSER TO MOST
OF THE DYNAMIC MODELS.
 
NEKI IS FORECAST TO CONTINUE INTENSIFYING OVER THE NEXT 48 HOURS.
SST VALUES WILL REMAIN IN THE 27 TO 28 DEGREE RANGE WITH LITTLE
VERTICAL WIND SHEAR FOR THE NEXT 36 HOURS. AFTER 36 HOURS...WEST TO
NORTHWEST SHEAR WILL INCREASE AND WATER TEMPERATURES WILL COOL.
THOSE CHANGES WILL CAUSE NEKI TO STEADILY WEAKEN AFTER 48 HOURS.

THE FORECAST TRACK SHOULD KEEP NEKI FAR ENOUGH NORTHEAST OF JOHNSTON
ISLAND TO KEEP TROPICAL STORM FORCE WINDS FROM REACHING THE ISLAND
BUT THERE IS ENOUGH UNCERTAINTY IN THE TRACK TO WARRANT KEEPING THE
TROPICAL STORM WATCH IN EFFECT FOR JOHNSTON. BY 72 HOURS...NEKI MAY
BE CLOSE TO THE ISLANDS OF THE PAPAHANAUMOKUAKEA NATIONAL MONUMENT
BETWEEN FRENCH FRIGATE SHOALS AND LISIANSKI ISLAND. LARGE SWELLS
FROM THE SOUTHEAST MAY REACH THE MONUMENT AS EARLY AS THURSDAY. 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      21/0900Z 16.3N 166.0W    75 KT
 12HR VT     21/1800Z 17.5N 166.9W    85 KT
 24HR VT     22/0600Z 19.0N 167.5W    95 KT
 36HR VT     22/1800Z 20.6N 168.2W   105 KT
 48HR VT     23/0600Z 22.0N 168.6W   110 KT
 72HR VT     24/0600Z 23.8N 168.9W   100 KT
 96HR VT     25/0600Z 25.5N 169.0W    90 KT
120HR VT     26/0600Z 27.0N 169.0W    80 KT
 
$$
FORECASTER DONALDSON